Hearing loud bangs in southern Ontario? It was likely an 'ice quake'

Residents across Toronto and beyond are reporting being awoken early Friday morning by loud booms, which experts say were frost quakes.

Frost quakes, also known as cryoseisms, occur after precipitation and bitterly cold temperatures.

“Ice can be very rigid at cold temperatures, and as it expands it’s trying to find room for itself and it can build up tremendous pressure,” Cathy Woodgold, a seismologist with Earthquake Canada, told CTV Toronto on Friday.

Woodgold said the pressure will often result in ice breaking or buckling, producing a loud sound and sometimes shaking ground.

“And if you’re close to it, it can be like an earthquake,” she said.

Woodgold said, however, that people shouldn’t be worried for their safety as frost quakes are not dangerous.

Nevertheless, the sounds were unfamiliar to many, sparking concern and widespread discussion on social media.

Cont. George Tudos of the Peel Regional Police said that early Friday morning the force received more than 100 calls.

“Everyone described it differently and that was why it was hard to categorize the calls we received,” he said. “We responded to all these calls and they were all unfounded. And after speaking to more people and witnesses we came to the determination they were these frost quakes.”

Tudos said he believes frost quakes were the cause of similar sounds that alarmed residents on Dec. 26, that also resulted in numerous calls to police.

CTV Toronto reporter Naomi Parness described the first loud boom at around 3:45 a.m. in the Vaughan area "like a large object hit my roof, almost like a wrecking ball went into the house."

She ran out of bed to make sure her children were safe and looked out the window to see if she could see anything.

She heard another two huge booms shortly thereafter, then more around 6 a.m.

"All my neighbours heard it, it was impossible to sleep through it and it sounded like it was coming from the house. I have never heard a sound like that," she told CTVNews.ca

One man wrote in an email to CP24 that he heard the first boom between 12:30 a.m. and 1 a.m. ET in the Maple area.

"We though it may be something fall on the roof, or someone trying to break in. Then after we heard so many. They were sounded like loud bangs at several intervals. What it could be? But we couldn't sleep the whole night," Kalpesh Shah wrote.

Similar noises were reported north of Toronto late earlier this week and on Christmas Eve. In the GTA, the temperature dropped to about -23C overnight with a wind child of -35.

Dave Phillips, senior climatologist with Environment Canada, says a wet 2013 coupled with cold temperatures in December has made it an ideal time for frost quakes.

“It’s the perfect storm for these ice quakes or frost quakes,” he told CTV News Channel, adding that people are more likely to hear the noises at night as sound carries further. “It’s sort of like nature yawning and groaning.”